Abrasive wheel



Jan. s, 1929.

H. K. SPENCER ABRASIVE WHEEL Filed Nov. 27; 1925- Jan. 8, 1929.

H. K. SPENCER ABRASDIVE WHEEL Filed Nov; 27. 1925 2 Sheets-Sheet 2lnvenior:

If. Spencer;

Patentedv Jan. 8 1929.

A Pics.

HENRY K.SPENCER, OF WINCHESTER, MASSACHUSETTS, ASSIGNOR TOIHE BLANCH-ARD MACHINE COMPANY, OF CAMBRIDGE, MASSACHUSETTS, A CORPORATION OFMASSACHUSETTS.

ABRAs'IvE WHEEL.

' Application filed November 27,1925. serial'ivo. 71,576.

' This invention relates to a novel abrasive wheel embodying a series ofblocks of abrajsive anaterial, and means to cause them to be held inplace and to permit them to beadjusted from time to tiir'ie tocompensate for wear, as well as to permit them to be replaced by newones, as occasion requires. N

The lllVBlltlOllWlll be best understood by reference to the followingdescription, wh

wheel exemplifying the invention;

Fig. 2 is asectional view on an enlarged scaleo'n line 22 of Fig. 1,looking in the direction of the arrows on said line:

-' "Fig. '7 is a sectional view n an en arged scale on line 7-7 of F 1g.5,1ook1ng 1n the Fig. 3 is a sectional View on line 33 of Fig-2, lookingin the direction of the arrows on said line;

Fig. 2, looking in the'di'i'ection of the arrows on said line; I a

F ig. 5 is a sectional view on 'an'en'larged scale on 1ine,55 of Fig.1,.looking in the direction of thearrows on said. line Fig. 6 is asectional view similar to Fig. 5, showing the abrasive blacker segmentin a differ'ent'position', and with a stop at its upper direction ofthe'a'rrows on said line; and I Fig. 8 1s a sectional view on a reducedscale on line 8+8 of Fig. 2, looking in the direci loosely through thedisk and threaded into tion of thel arrows on said line.

first more particularl to Fig. 1, the wheel comprises a chuck b0 yincluding'a ring 11' and a disk 12, 'suitablysecuredto each other,

asby cap screws ,13 (see Fig. 2), extending the ring. The chuck presentsa holder for a series of blocks or segments of abrasive materiahwhich,as shown in Fig. 1, are in [spaced relationship with oneanother.Gentrifugal force is util zed to exert pressure on the blocks to holdthem in'place. Thisis conveniently accomplished in the present exampleby making each block wedge-shaped,

with the small end of the wedge outward, and

V and mounted Fig. 4 is a sectional View on line 4-4 of by providing thering 11 with a-simila'rlyshapedreces's 15. In other-words, each blockhas sides which converge in an outwarddirection 'froin the axis of'thewheel, and the recess has similarly convergingsides, with which "thesides of the block contact. 'Looking at it in another way, the ring maybe said to present a series of wedges interposed-between the blocks. Thedepth of the'recess,

of course, is such that the small 'en'dof the wheel'is not running,clamping means are including clamping bolts 16,'nuts l7, and yokes 18,each spanning twoadjacent blocks,

bolt, thereby to equalize. the clamping "pressure between the two"blocks. It should here be mentioned that the weight of these yokes,bolts and nuts, is added to'that of the blocks in uti'li'zingcentrifugalfioi'ce to clamp" the latter when the wheel is running. Eachbolt has a loose 'fit in an e eningfeo provided in thering ll, and eachnut is received in a periphery of the wheel. In order that the bolt and;itsnut may be lubricated, and water excluded from their workingsurfaceafthe nut in the present example presents a chamber 23 to receiveasupply of'grease, "some provided, the same 1n thepresent' example on apivot 19on its associated .chamber 21 presented the ring} The nut ofwhich, asthe nut screwed into. place, v squeezes out along thecontacting'surfaces'of V the bolt ancl nut Herein, the bolt is provided' with alongitud'inal groove 24, extending from the end of the boltto a point some distance beyond the nut, thereby to afford a passageforgrease to work its way out along the bolt, and to enter the clearancespace be tween the bolt and, the openingfl20, thereby to exclude fromthe working surfaces water which might otherwise enter and cause theworking surfaces tofrust. N I

In'the presentembodiment the yoke does not contact with. the two blockswhich it clamps, but instead it rests against two shoes from the axis ofthe wheel a sufficient amount and of accommodating themselves to the 25,which contact with the blocks, and these shoes are supported in such amanner that, while they are capable of moving toward and shoe onv acomparatively stiff spring 26 (see. Figs. 5 and 7), which is secured tothe chuck. body, herein by a ring 27, which, as shown in e Fig. 2, issecured to the ring 11 by cap screws "28 extending loosely. through lugs29 pre :sented by the ring 11, said screws being,

threaded into the ring 27. Referring again to Figs. 5 and 7, each springis suitably securedto the ring 27, as. by rivets 30, and to the 7 shoe25, as by rivets 81. Herein, as shown in Fig. 5, the. lower end of thespring. extends into a groove 82, presented by the shoe. The

spring, being inextensible, prevents movement of the shoe lengthwise ofthe chuck body axis, and being wide. (see Fig. 3), preventscircumferential movement of the shoe. However, advantage is taken of theflexibility of I the spring in other directions. For example,

the spring bends under the outward thrust 1 of "the yoke, and not onlyallows the shoe to is alsocapableof twisting, and thereby allowmoveoutward, but also to align itself vertically with the faceof'the block.The spring 'ing the shoe to'align itself horizontally with i the face ofthe block. As a means to prevent I lugs 33 on the shoes, underlying theyoke'and the yoke and the bolt from rotating about the axis'ofthelatter, the yoke and the'shoes have suitable interengaging means,herein engaged'by the latter.

I clamping means is eifectiveto prevent the blocks frombeing forced inan upward direc-. .t'ion into the chuck body. Under some ex-.-

'ceptional circumstances, it may be desirable to provide a positivestop" to prevent the;

1 blocksfrom being forced up into-the chuck Q body. If the blocks are ofsufficient length, the positive stop may be presented by the disk 1 2above the blocks, the disk in the present casebeing provided withanabutment 34 (see Fi 5), which limitsupward movement of thlgblocks.l/Vhen finally the blocks have been worn away to a considerable extent,so as to require adjustment in a downward direction (see1Fig. 6), upwarddisplacement of the. I blocks may be prevented by the provision of studs35 threaded into the ring ll, and pre senting stops 36 overlyingtheupperends of the blocks; Trapped holes. 37 may be'provided at variousheights toreceive the studs. As a means toafford protection to theclamping devices, from the water supplied to the interior of the wheelduring the grindrng operatlon, there is provided in the presentembodiment a guard comprising a ring 38 Under most clreumstances, thedescribed secured to and depending from-the disk 12,

like a skirt.

Having thus described one embodiment of the invention, but withoutlimiting myself thereto, what I claim and desire by Letters Patent tosecure is: l 1

1. In an abrasive wheel, the combination of a series of blocksofabrasivematerial, and a holder'therefor comprising a series of yokeseach-spanning two blocks, and a series of clamping bolts fpivotallyconnected to said yokes, respectively, and arranged to permit said yokesto rock blocks to cause them to exert clamping pres.- sure onsaidblocks. a

2. In an abrasive wheel, the combination of a. series of blocks ofabrasive material, and a holder therefor comprising a series of yokeseach spanning two blocks, there being but one yoke. to each two blocks,asseries of radial toward and from said bolts and nuts to cause saidyokes to clamp said blocks, there being but one bolt and one nut to eachtWo blocks, said yokes being setion, and means to urge saidshoes'toward.

said blocks and to urge said-blocks toward said abutments. I

4. In an abrasive'wheel, the combination of a series of blocks ofabrasive material, a chuck bodypresenting abutments for said blocks, aseries of shoes engaging said blocks, springs supporting said shoesresiliently in radial directions and rigidly in an axial direction, andmeans to urge said shoes toward said blocks and to urge said blockstoward said abutments.

5. In an abrasive wheel, the combination of bodypresentingabutments forsaid blocks, a seriesof shoes resiliently supported by said 'a seriesofblocks of abrasive material, a chuck chuck body and engaging saidblocks, a series of clamping yokes each engaging two of said shoes, anda series of clamping bolts, to'ca'use said yokes to urge said shoestowardjsaid blocks and to urge'said, blocks toward-said iabutments. I

6. In an abrasive wheel, the combination of a series of blocks ofabrasive material, a chuck body presenting abutments for said blocks, aseries of shoes resiliently supported a seriesof clamping yokes eachengaging two of sa1d shoes, a series of clamping bolts and nuts to causesaid yokes to urge said shoes toa series of blocks of'abrasive material,'a'chuck V by said chuck body andengaging said blocks,

body presenting abutments for said blocks, a abutments, and meanspresented by said shoes series of shoes flexibly supported by said andsaid yokes to prevent rotation of said chuck body and engaging saidblocks, a series yokes. 10 of clamping yokes each engaging two of saidIn testimony whereof, I have signed my 5 shoes, a series of clampingbolts and nuts to name to this specification.

cause said yokes to urge said shoes toward said blocks and to urge saidblocks toward said HENRY K. SPENCER.

